massproducer said:
Now while Stoney, you know I respect and honour your opinions always, I have to kind of disagree with some of your statements. I have just started using Advanced nutrients, Sweet Leaf and I must say, it is doing everything it said that it would do, while it is not just Molasses, it is a major component. I can not give you any other information other then practical. I was a sceptic and would have never bought this but my hydro guy gave me a 1 liter sample, and it sure is making my flowers smell sweet, almost too sweet.
It somewhat makes sense to me that sugars would help with terpene development as terpenes melucar makeup is C5H8, so 5 carbon molecules and 8 hydrogen, sucrose is carbon-hydrogen and oxygen, so while i am not a scientist it doesn't seem that much of a stretch to me. Also sucrose matches a plants carbohydrate profile exactly, it is a plant-produced sugar, just not that plant. But I will just leave this one alone because I honestly do not know enough about the sweetening side of things.
We have to remember the difference between the sucrose developed *by* the plant as opposed to sucrose that is *not* developed by the plant. We're discussing the resulting actions of a plant to the addition of sucrose to the plants environment, not the plants handling of the sucrose that it develops in the natural evolution of osmosis.
Semi-permeable membranes are very thin layers of material (cell membranes are semi-permeable) which allow some things to pass through them but prevent other things from passing through.
Cell membranes will allow small molecules like Oxygen, water, Carbon Dioxide, Ammonia, Glucose, amino-acids, etc. to pass through. Cell membranes will not allow larger molecules like Sucrose, Starch, protein, etc. to pass through.
When plant cells are placed in concentrated sugar solutions they lose water by osmosis and they become "flaccid"; this is the exact opposite of "turgid". If you put plant cells into concentrated sugar solutions and look at them under a microscope you would see that the contents of the cells have shrunk and pulled away from the cell wall: they are said to be plasmolysed.
Molasses (average NPK 1-0-5) contains potash, sulfur, and many trace minerals, it can serve as a nutritious soil amendment. Molasses is also an excellent chelating agent.
However, Plasmolysis is the separation of plant cell cytoplasm from the cell wall as a result of water loss. It is unlikely to occur in nature, except in severe conditions. Plasmolysis is induced in the laboratory by immersing a plant cell in a strongly saline or sugary solution, so that water is lost by osmosis.
If onion epidermal tissue is immersed in a solution of calcium nitrate, cells rapidly lose water by osmosis and the protoplasm of the cells shrinks. This occurs because the calcium and nitrate ions freely permeate the cell wall and encounter the selectively permeable plasma membrane.
The large vacuole in the center of the cell originally contains a dilute solution with much lower osmotic pressure than that of the calcium nitrate solution on the other side of the membrane.
The vacuole thus loses water and becomes smaller. The space between the cell membrane and the cell wall enlarges and the plasma membrane and the protoplasm within it contract to the center of the cell. Strands of cytoplasm extend to the cell wall because of plasma membrane-cell wall attachment points. Plasmolysed cells die unless they are transferred quickly from the salt or sugar solution to water.
Thus, any concentration of sucrose into a plants feeding nutrients will detract from the plants growth due to the onset of Plasmolysis and it's results as shown in the example above.
The addition of properly fermented molasses or other sugary substances is an exception in that those fermented substances will not be the active ingredient of the nutrient base, but a substance which accelerates and promotes beneficial microbial action in the root area of a plant.
This beneficial microbial action is what enables the plant to perform it's natural functions to the best of it's ability when the point of maximum nutrient, oxygen and water uptake is approached.
Some of the sources that this information is derived from include:
Dainty, J. (1976) Water relations of plant cells. In Transport in Plants II, Part A, Cells, U. Lüttge and M. G. Pitman, eds. Encyclopedia of Plant Physiology, New Series, Vol. 2. Springer-Verlag, Berlin, pp. 1235.
Green, P. B. (1968) Growth physics in Nitella: A method for continuous in vivo analysis of extensibility based on a micro-manometer technique for turgor pressure. Plant Physiol. 43: 11691184.
Green, P. B., and Stanton, F. W. (1967) Turgor pressure: Direct manometric measurement in single cells of Nitella. Science 155: 16751676.
Pickard, W. F. 1983. The ascent of sap in plants. Prog. Biophys. Mol. Biol. 37: 181229.
Scholander, P. F., Hammel, H. T., Bradstreer, E. D., and Hemmingsen, E. A. (1965) Sap pressure in vascular plants. Science 148: 339346.
Slavik, B. (1974) Methods of Studying Plant Water Relations. Academia, Prague.
Steudle, E. (1993) Pressure probe techniques: Basic principles and application to studies of water and solute relations at the cell, tissue and organ level. In Water Deficits: Plant Responses from Cell to Community, J. A. C. Smith and H. Griffiths, eds., BIOS Scientific, Oxford, pp. 536.
Tyree, M. T. 1976. Negative turgor pressure in plant cells: Fact or fallacy? Can. J. Botany 54: 27382746.